Connect Segments

Provides a method to manually connect unconnected segments within a river network. The nearest endpoint (or vertex) of the second segment is added as a new vertex to the first, and the network topology is then updated.

connectsegs(connect, connectto, nearestvert = TRUE, rivers,
  calcconnections = TRUE)

Arguments

connect	The segment(s) to connect to the network. Typically, this is the segment that is disconnected from the rest of the river network. A vector of segments may be used.
connectto	The segment(s) to connect it (them) to. Typically, this is a segment that is connected to the rest of the river network. A vector of segments may be used, corresponding to that used in connect=.
nearestvert	Whether to connect at the nearest vertex and split the segment (FALSE), or connect at the nearest endpoint (TRUE). Defaults to TRUE. A vector may be used, corresponding to those used in connect= and connectto=.
rivers	The river network object to use.
calcconnections	Whether to recalculate all connections. Defaults to TRUE. Setting to FALSE is not recommended unless many connections are to be made, in which case connections can be calculated afterward.

Value

A new river network object with the specified segments connected (see rivernetwork)

Note

This function is called within cleanup, which is recommended in most cases.

See also

line2network

Examples

data(Koyukuk0)
plot(Koyukuk0, ylim=c(1930500,1931500), xlim=c(194900,195100))
topologydots(Koyukuk0, add=TRUE)

Koyukuk0.1 <- connectsegs(connect=21, connectto=20, rivers=Koyukuk0)
#> Note: any point data already using the input river network must be re-transformed to river coordinates using xy2segvert() or ptshp2segvert().
plot(Koyukuk0.1,ylim=c(1930500,1931500), xlim=c(194900,195100))
topologydots(Koyukuk0.1, add=TRUE)

# or the vector version
zoomtoseg(seg=21:23, rivers=Koyukuk0)
Koyukuk0.2 <- connectsegs(connect=c(20,21,22), connectto=c(21,22,23),
    nearestvert=c(FALSE,FALSE,TRUE), rivers=Koyukuk0)
#> Note: any point data already using the input river network must be re-transformed to river coordinates using xy2segvert() or ptshp2segvert().
zoomtoseg(seg=21:23, rivers=Koyukuk0.2)
topologydots(Koyukuk0.2, add=TRUE)